GMT G5111T11UF Micro-power step-up dc/dc converters in sot-23-5 Datasheet

G5111
Global Mixed-mode Technology Inc.
Micro-power Step-Up DC/DC Converters in SOT-23-5
Features
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General Description
Configurable Output Voltage Up to 28V
20µA Quiescent Current
<1µA Shutdown Current
<1µA Shutdown Pin Current
Supply Range from 2.5V to 6.5V
Low VDS(on): 250mV (ISW=300mA)
Tiny SOT-23-5 Package
The G5111 boost converter is designed for small/ medium size LCD panel of high bias voltage.
Due to a typical 20µA quiescent current and 2.5V~
6.5V supply voltage range, it is suitable for battery
powered portable applications. Such as PDAs and
Handheld Computers. When the IC sets to shutdown
mode, it only consumes less than 1µA.
Applications
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Furthermore, the 350mA current limit, 500ns fixed
minimum off-time and tiny SOT-23-5 package facilitates the use of smaller inductor and other surface-mount components to minimize the PCB size in
those space-conscious applications.
STN/TFT LCD Bias
Personal Digital Assistants (PDAs)
Handheld Computers
Digital Still Cameras
Cellular Phones
WebPad
White LED Driver
Local 3V to 5V Conversion
To control the IC, no other external current is needed
for the shutdown pin. It typically consumes less than
1µA of full supply range.
Ordering Information
ORDER
NUMBER
ORDER NUMBER
(Pb free)
MARKING
TEMP. RANGE
PACKAGE
G5111T11U
G5111T11Uf
51xx
-40°C ~ +85°C
SOT-23-5
G5111T12U
G5111T12Uf
52xx
-40°C ~ +85°C
SOT-23-5
Pin Configuration
SW
1
Typical Application Circuit
5
VCC
10µH
GND 2
G5111 T11
G963
VCC
4
FB 3
SW
SHDN
1M
G5111
SOT-23-5
SHDN
SHDN 1
VCC 2
20V
12mA
VIN
2.5V to 4.2V
5
FB
4
SW
4.7µF
1µF
FB
GND
62k
G5111 T12
G963
GND 3
SOT-23-5
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Global Mixed-mode Technology Inc.
Absolute Maximum Ratings
Junction Temperature ......….......….........…........+125°C
Storage Temperature…………........…..-65°C to +150°C
Reflow Temperature (soldering, 10sec)…………260°C
SW to GND…………………………………..-0.3V to +30V
FB to GND…………… ……………………….-0.3V to VCC
VCC, SHDN to GND.............................…....-0.3V to +7V
Operating Temperature Range (Note 1)..-40°C to +85°C
Stress beyond those listed under “Absolute Maximum Rating” may cause permanent damage to the device.
Electrical Characteristics
(VCC = 3.6V, V SHDN = 3.6V, TA = 25°C)
PARAMETER
CONDITIONS
Input Voltage Range
Not Switching
V SHDN = 0V
Quiescent Current
FB Comparator Trip Point
Output Voltage Line Regulation
FB Pin Bias Current (Note 2)
Switch Off Time
Switch VDS(ON)
2.5V<VIN<6.5V
VFB = 1.2V
VFB > 1V
VFB < 0.6V
ISW = 300mA
MIN
TYP
MAX
UNITS
2.5
-----
--20
0.1
6.5
35
1
V
µA
µA
1.18
1.2
1.22
V
---------
-0.05
30
500
1.6
--80
-----
%/V
nA
ns
µs
---
250
350
mV
Switch Current Limit
300
350
400
mA
SHDN Pin Current
---
0.1
1
µA
SHDN Input Voltage High
0.9
---
---
V
SHDN Input Voltage Low
---
---
0.25
V
---
0.01
5
µA
Switch Leakage Current
Switch Off, VSW = 28V
Note 1: The G5111 are guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the
-40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 2: Bias current flows into the FB pin.
Block Diagram
L1
VIN
VOUT
C2
C1
BIAS
VOUT
R1
FB
+
SW
SHDN
VCC
SHUTDOWN
LOGIC
PUMP CONTROL
OC
DRIVER
COMP
ERROR
COMP
en_sw
+
R2
1.2V
TOFF PULSE
CONTROL
VREF
GND
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Global Mixed-mode Technology Inc.
Typical Performance Characteristics
(VCC=+3.6V, V SHDN =+3.6V, L=10µH, TA=25°C, unless otherwise noted.)
Output Voltage vs. Load Current
21
21
20.5
20.5
Output Voltage (V)
Output Voltage (V)
Output Voltage vs. Input Voltage
IOUT=1mA
20
IOUT=10mA
19.5
19
VIN=2.7V
20
VIN=4.2V
19.5
19
2.5
3
3.5
4
4.5
5
5.5
1
2
3
5
6
7
8
9
10
Quiescent Current vs. Temperature
Efficiency vs. Load Current
50
90
Quiescent Current (µA)
VIN=4.2V
85
80
Efficiency (%)
4
Load Current (mA)
Input Voltage (V)
VIN=3.6V
75
70
VIN=2.7V
65
60
40
VIN=4.2V
30
20
VIN=2.7V
55
10
50
0.1
1
10
-20
100
0
40
60
80
100
Feedback Voltage vs. Temperature
Vds_on vs. Temperature
1.22
Feedback Voltage (V)
500
Switch Vds_on (mV)
20
Temperature (°C)
Load Current (mA)
400
VIN=2.7V
300
200
VIN=4.2V
100
1.21
VIN=2.7V
1.2
1.19
VIN=4.2V
1.18
-20
0
20
40
60
80
100
-20
Temperature (°C)
0
20
40
60
80
100
Temperature (°C)
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Global Mixed-mode Technology Inc.
Typical Performance Characteristics (continued)
FB Bias Current vs. Temperature
Switch Current Limit vs. Temperature
450
VIN=2.7V
Peak Current (mA)
Feedback Bias Current (nA)
30
25
20
VIN=4.2V
400
VIN=4.2V
350
VIN=2.7V
300
250
15
-20
0
20
40
60
80
-20
100
0
20
40
60
80
100
Temperature (°C)
Temperature (°C)
Line Transient
Load Transient
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Global Mixed-mode Technology Inc.
Pin Description
PIN
NAME
FUNCTION
4
3
SW
GND
Switch Pin. The drain of the internal NMOS power switch. Connect this pin to inductor.
Ground.
Feedback Pin. Set the output voltage by selecting values for R1 and R2 (see Block Diagram):
3
5
FB
4
1
SHDN
5
2
VCC
T11
T12
1
2
R1 = R2
VOUT
-1
1 .2
Active-Low Shutdown Pin. Tie this pin to logic-high to enable the device or tied it to logic-low
to turn this device off.
Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible.
Function Description
Where VD = 0.4V (Schottky diode voltage), ILIM =
350mA and tOFF = 500ns. A larger value can be used
to lightly increase the available output current, but limit
it to about twice the calculating value. When too large
of an inductor will increase the output voltage ripple
without providing much additional output current. In
varying VIN condition such as battery power applications, use the minimum VIN value in the above equation. A smaller value can be used to give smaller
physical size, but the inductor current overshoot will be
occurs (see Current Limit Overshoot section).
The G5111 is a boost converter with a NMOS switch
embedded (refer to Block Diagram). The boost cycle
is getting started when FB pin voltage drop below
1.2V as the NMOS switch turns on. During the switch
on period, the inductor current ramps up until 350mA
current limit is reached. Then turns the switch off,
while the inductor current flows through external
schottky diode, and ramps down to zero. During the
switch off period, the inductor current charges output
capacitor and the output voltage is boosted up. This
pumping mechanism continues cycle by cycle until
the FB pin voltage exceed 1.2V and entering the none
switching mode. In this mode, the G5111 consumes
as low as 20µA typically to save battery power.
Inductor Selection—SEPIC Regulator
For a SEPIC regulator using the G5111, the approximate inductance value can be calculated by below
formula. As for the boost inductor selection, a larger or
smaller value can be used.
Applications Information
Choosing an Inductor
There are several recommended inductors that work
well with the G5111 in Table 1. Use the equations and
recommendations in the next few sections to find the
proper inductance value for your design.
L=2
PART
VALUE(µH) MAX DCR (Ω)
4.7
10
22
4.7
10
4.7
10
0.26
0.30
0.92
0.11
0.18
0.16
0.20
4.7
10
22
0.09
0.16
0.37
VENDOR
Murata
www.murata.com
IPEAK = ILIM +
Sumida
www.sumida.com
VIN(MAX) - VSAT
x 100ns
L
Where VSAT = 0.25V (switch saturation voltage). When
the systems with high input voltages and uses smaller
inductance value, the current overshoot will be most
apparent. This overshoot can be useful as it helps increase the amount of available output current. To use
small inductance value for systems design, the current
limit overshoot can be quite high. Even if it is internally
current limited to 350mA, the power switch of the
G5111 can operate larger currents without any problem, but the total efficiency will suffer. The IPEAK is keep
below 500mA for the G5111 will be obtained best performance.
Coilcraft
www.coilcraft.com
Inductor Selection—Boost Regulator
The appropriate inductance value for the boost regulator application may be calculated from the following
equation. Select a standard inductor close to this
value.
L=
x tOFF
Current Limit Overshoot
The G5111 use a constant off-time control scheme,
the power switch is turned off after the 350mA current
limit is reached. When the current limit is reached and
when the switch actually turns off, there is a 100ns
delay time. During this time, the inductor current exceeds the current limit by a small amount. The formula
below can calculate the peak inductor current.
Table 1. Recommended Inductors
LQH3C4R7
LQH3C100
LQH3C220
CD43-4R7
CD43-100
CDRH4D18-4R
7
CDRH4D18-100
DO1608-472
DO1608-103
DO1608-223
VOUT + VD
ILIM
VOUT-VIN(MIN)+VD
x tOFF
ILIM
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Global Mixed-mode Technology Inc.
Capacitor Selection
Low ESR (Equivalent Series Resistance) capacitors
should be used at the output to minimize the output
ripple voltage and the peak-to-peak transient voltage.
Multilayer ceramic capacitors (MLCC) are the best
choice, as they have a very low ESR and are available
in very small packages. Their small size makes them a
good match with the G5111’s SOT-23-5 package. If
solid tantalum capacitors (like the AVX TPS, Sprague
593D families) or OS-CON capacitors are used, they
will occupy more volume than a ceramic ones and the
higher ESR increases the output ripple voltage. Notice
that use a capacitor with a sufficient voltage rating.
A low ESR surface-mount ceramic capacitors also
make a good selection for the input bypass capacitor,
which should be placed as close as possible to the
G5111. A 4.7µF input capacitor is sufficient for most
applications.
recommended. Many different manufacturers make
equivalent parts, but make sure that the component is
rated to operate at least 0.35A. To achieve high efficiency, the average current rating of the Schottky diodes should be greater than the peak switching current. Choose a reverse breakdown voltage greater
than the output voltage.
Lowering Output Voltage Ripple
The G5111 supplies energy to the load in bursts by
ramping up the inductor current, then delivering that
current to the load. To use low ESR capacitors will
help minimize the output ripple voltage, but proper
selection of the inductor and the output capacitor also
plays a big role. If a larger inductance value or a
smaller capacitance value is used, the output ripple
voltage will increase because the capacitor will be
slightly overcharged each burst cycle. To reduce the
output ripple, increase the output capacitance value or
add a 10pF feed-forward capacitor in the feedback
network of the G5111 (see the circuits in the Typical
Applications section). To add this small, inexpensive
10pF capacitor will greatly reduce the output voltage
ripple.
Diode Selection
For most G5111 applications, the high switching frequency requires a high-speed rectifier Schottky diodes,
such as the Motorola MBR0530 (0.5A, 30V) with their
low forward voltage drop and fast switching speed, are
Typical Applications
Boost Converter
L1
4.7µH
SEPIC Converter
5V
50mA
VIN
2.5V to 4.2V
VCC
VCC
SW
G5111
SHDN
GND
D1
3.3V
60mA
VIN
2.5V to 4.2V
SW
L2
10µH
R1
390k
C1
4.7µF
C3
1µF
L1
10µH
D1
R1
470k
G5111
C2
22µF
SHDN
FB
C1
4.7µF
R2
120k
GND
C2
22µF
FB
R2
270k
L1,L2:MURATA LQH3C100K24
D1:MOTOROLA MBR0520
L1:MURATA LQH3C4R7M24
D1:MOTOROLA MBR0520
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Global Mixed-mode Technology Inc.
White LED Driver
L1
10µH/0.5A
D1
VBAT
2.5V~5.5V
MBR0530
C1
4.7µF
C2
1µF
SW
VCC
D2(Optional)
27V
G5111
ON/OFF Control
FB
SHDN
GND
R2
120k_1%
R3
VBIAS(+3.3V)
R1
30_1%
308k_1%
PWM Dim
R4
660k_1%
Dimming Ratio>50:1
Drive 2~8 White LEDs
PWM Dimming Control
VH=3.3V
VL=0V
Freq=160~240Hz
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Global Mixed-mode Technology Inc.
Package Information
C
D
L
E
H
θ1
e1
e
A
A2
A1
b
Note:
1. Package body sizes exclude mold flash protrusions or gate burrs
2. Tolerance ±0.1000 mm (4mil) unless otherwise specified
3. Coplanarity: 0.1000mm
4. Dimension L is measured in gage plane
SYMBOLS
DIMENSIONS IN MILLIMETERS
MIN
NOM
MAX
A
1.00
1.10
1.30
A1
A2
b
C
D
0.00
0.70
0.35
0.10
2.70
----0.80
0.40
0.15
2.90
0.10
0.90
0.50
0.25
3.10
E
e
e1
H
1.40
--------2.60
1.60
1.90(TYP)
0.95
2.80
1.80
--------3.00
L
θ1
0.37
------
-----
1º
5º
9º
Taping Specification
PACKAGE
Q’TY/BY REEL
SOT-23-5
3,000 ea
Feed Direction
SOT-23-5 Package Orientation
GMT Inc. does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and GMT Inc. reserves the right at any time without notice to change said circuitry and specifications.
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